U.S. patent application number 11/144387 was filed with the patent office on 2006-12-07 for radiator fan shroud with flow directing ports.
This patent application is currently assigned to PACCAR Inc. Invention is credited to Brian G. Campbell, Kevin Chou, Dan Farmer, Adam J. Hailey, Tim L. Schick, Alec C. Wong.
Application Number | 20060272800 11/144387 |
Document ID | / |
Family ID | 37480420 |
Filed Date | 2006-12-07 |
United States Patent
Application |
20060272800 |
Kind Code |
A1 |
Wong; Alec C. ; et
al. |
December 7, 2006 |
Radiator fan shroud with flow directing ports
Abstract
A radiator fan shroud (100) is disclosed that is adapted to be
attached to a vehicle radiator (96)--for example, the radiator of a
Class 8 truck. The fan shroud includes a peripheral cover portion
(112) and a ring assembly (102) that encloses the blades of the
engine-driven radiator fan (88). The ring assembly may be formed
integrally with the peripheral cover portion or may include a
separable ring extension (120). The ring assembly includes a
plurality of ports (104) defined by vanes (106) at the rearward
portion of the ring assembly. The ports are selectively positioned
to manage the airflow in the engine compartment, directing the
airflow towards selected locations. The vanes may be fluted. The
fan shroud may be formed from two or more pieces that cooperatively
form the fan shroud, to facilitate installation and maintenance of
the fan shroud.
Inventors: |
Wong; Alec C.; (Bellevue,
WA) ; Farmer; Dan; (Coupeville, WA) ;
Campbell; Brian G.; (Seattle, WA) ; Hailey; Adam
J.; (Deer Park, WA) ; Chou; Kevin; (Redmond,
WA) ; Schick; Tim L.; (Duvall, WA) |
Correspondence
Address: |
CHRISTENSEN, O'CONNOR, JOHNSON, KINDNESS, PLLC
1420 FIFTH AVENUE
SUITE 2800
SEATTLE
WA
98101-2347
US
|
Assignee: |
PACCAR Inc
Bellevue
WA
|
Family ID: |
37480420 |
Appl. No.: |
11/144387 |
Filed: |
June 2, 2005 |
Current U.S.
Class: |
165/120 |
Current CPC
Class: |
F01P 11/10 20130101;
F01P 2070/50 20130101; F01P 2001/005 20130101; F01P 5/06
20130101 |
Class at
Publication: |
165/120 |
International
Class: |
B29C 47/88 20060101
B29C047/88 |
Claims
1. A cooling system for a vehicle comprising: a radiator having a
front side and a rear side; a fan having a plurality of blades, the
plurality of blades disposed near the rear side of the radiator,
the fan being operable to draw air in a direction from the front
side of the radiator towards the rear side of the radiator; and a
fan shroud having a peripheral portion that attaches to the
radiator, a circular ring portion that extends from the peripheral
portion and around the fan blades; wherein the ring portion
includes a plurality of vanes defining a plurality of ports that
direct airflow laterally.
2. The cooling system of claim 1, wherein at least one of the
plurality of ports is positioned to direct an airflow towards an
auxiliary component in an engine compartment of the vehicle.
3. The cooling system of claim 1, wherein at least one of the
plurality of ports is positioned to direct an airflow away from an
auxiliary component in an engine compartment of the vehicle.
4. The cooling system of claim 1, wherein the auxiliary component
is selected from the following--an alternator, a starter motor, an
oil cooler, an electronic control, a pollution control, and a fluid
reservoir.
5. The cooling system of claim 1, wherein the vanes have varying
lengths.
6. The cooling system of claim 1, wherein the fan shroud peripheral
portion and the fan shroud circular ring portion are formed
integrally.
7. The cooling system of claim 1, wherein the fan shroud ring
portion comprises a main ring portion and a ring extension that is
attached to the main ring portion.
8. The cooling system of claim 1, wherein the fan shroud comprises
an upper shroud portion and a lower shroud portion that attaches to
the upper shroud portion.
9. The cooling system of claim 1, wherein the fan shroud further
comprises a downwardly extending airflow deflector.
10. The cooling system of claim 1, wherein at least some of the
plurality of vanes are fluted.
11. A radiator fan shroud comprising: a peripheral portion adapted
to attach to a radiator, and a tubular ring portion that extends
from the peripheral portion, wherein the tubular ring portion
includes a plurality of vanes defining a plurality of ports that
direct airflow laterally.
12. The radiator fan shroud of claim 10, wherein at least one of
the plurality of ports is positioned to direct an airflow toward an
auxiliary component in an engine compartment of a vehicle.
13. The radiator fan shroud of claim 10, wherein at least one of
the plurality of ports is positioned to direct an airflow away from
an auxiliary component in an engine compartment of a vehicle.
14. The radiator fan shroud of claim 10, wherein the plurality of
vanes have varying lengths.
15. The radiator fan shroud of claim 10, wherein the fan shroud
peripheral portion and the fan shroud tubular ring portion are
formed integrally.
16. The radiator fan shroud of claim 10, wherein the fan shroud
ring portion comprises a main ring portion and a ring extension
that is attached to the main ring portion.
17. The radiator fan shroud of claim 10, wherein the fan shroud
comprises an upper shroud portion and a lower shroud portion that
attaches to the upper shroud portion.
18. The radiator fan shroud of claim 10, wherein the fan shroud
further comprises a downwardly extending airflow deflector.
19. The radiator fan shroud of claim 10, wherein at least some of
the plurality of vanes are fluted.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to engine cooling
systems for vehicles such as trucks and, more particularly, to
components for managing airflow through the radiator and into the
engine compartment.
BACKGROUND OF THE INVENTION
[0002] In typical automotive engine cooling systems, a coolant
(primarily water) is circulated through the engine to transport
heat away from the engine. Relatively cool water is transported
through channels in the engine and transports away excess heat from
the engine. The heated water then exits the engine and the
relatively hot water circulates through a series of tubes in an
external radiator located at the front of the vehicle. The series
of tubes is generally provided with fins to improve the heat
transfer performance. Airflow through the radiator convectively
transports heat away, thereby cooling the circulating coolant.
Relatively low temperature coolant then exits the radiator and is
returned to the engine. An engine-driven fan is typically provided
on the rear side (engine side) of the radiator to enhance the
airflow through the radiator, significantly increasing the heat
transfer from the circulating coolant. The fan is particularly
important for maintaining airflow through the radiator when the
vehicle is not moving. The fan is oriented to draw air rearwardly
through the radiator and past the fan into the engine compartment.
A radiator fan shroud is often provided, the fan shroud attaching
to the rear side of the radiator and including a circular ring
portion that surrounds the fan blades.
[0003] The coolant acts as a heat sink for the engine, removing
waste heat and controlling the engine temperature. The more
controlled the temperature of the coolant, the better the
performance of the engine. Generally, increased airflow through the
radiator will increase the convective heat transfer away from the
coolant and improve the effectiveness of the radiator. For example,
it is known that performance of the fan is better if the clearance
between the fan blade tips and the fan shroud ring is minimized.
Therefore, the shroud ring is typically relatively rigid and
dimensioned to closely accommodate the fan blades.
[0004] In prior art vehicles, little consideration is given to the
airflow after it has passed through the radiator and past the fan.
The air typically encounters the engine block just downstream of
the fan and is thereby turned outwardly within the engine
compartment, creating a relatively high pressure region directly
behind the fan.
[0005] Of course, during operation the engine compartment is a
relatively warm environment and certain components within the
engine compartment get particularly warm, either by receiving heat
from other components or from internally generated heat (for
example, the alternator, oil cooler, and the like). Also, there are
many components in the engine compartment that may benefit if the
mean and/or peak temperature that such components are exposed to
were decreased (for example, hoses, belts, cables, seals, and the
like). In addition, it will be appreciated that lower mean and/or
peak temperature conditions in the engine compartment or in
particular regions in the engine compartment would allow the
designer a wider range of material choices for auxiliary
components, thereby leading to potential savings in weight,
production costs, and/or reliability.
[0006] There is a need, therefore, for systems and methods for
improving the effectiveness of the radiator cooling--for example,
by increasing the airflow through the radiator--and for systems and
methods for decreasing the temperature within the engine
compartment--and especially for providing directed cooling airflow
to specific components or in certain directions in the engine
compartment.
SUMMARY OF THE INVENTION
[0007] A cooling system for a motor vehicle is disclosed. The
system is suitable for use in a variety of different vehicle types
and the currently preferred embodiment disclosed herein is
particularly suitable for large commercial trucks. The vehicle
cooling system includes a conventional radiator for removing waste
heat from the engine coolant. A radiator fan, generally
engine-driven, is disposed rearward of the radiator and is adapted
to pull air through the radiator. A fan shroud attaches to the rear
face of the radiator and includes a ring portion that houses the
fan blades, such that the airflow drawn by the fan is substantially
limited to air pulled through the radiator. The rearward end of the
ring portion of the fan shroud includes a plurality of
spaced-apart, rearward projections or vanes that cooperatively
define a plurality of ports. The ports are preferably strategically
positioned to direct the airflow rearward of the fan blades in
desired directions--for example, to provide supplemental cooling to
particular components in the engine compartment. The ports also
provide additional outflow area rearward of the fan blades (as
compared to a solid ring portion having the same length), thereby
lowering the pressure between the fan blades and the engine and
improving the fan efficiency.
[0008] In an embodiment of the invention, the ports are positioned
to direct airflow toward or away from an alternator, starter motor,
oil cooler, electronic control device, pollution control device,
and/or fluid reservoir.
[0009] In an embodiment of the invention, the vanes on the ring
portion of the fan shroud are not all the same length and are
fluted.
[0010] In an embodiment of the invention, the ring portion of the
fan shroud is formed integrally with the peripheral portion of the
fan shroud.
[0011] In another embodiment of the invention, the ring portion
includes a separable ring extension.
[0012] In an embodiment of the invention, the fan shroud is formed
of an upper portion that is separable from the lower portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated as the same
become better understood by reference to the following detailed
description, when taken in conjunction with the accompanying
drawings, wherein:
[0014] FIG. 1 is a schematic diagram of an engine compartment of a
prior art truck showing the radiator, fan shroud, fan, and engine
block;
[0015] FIG. 2 is a schematic diagram of an engine compartment,
showing a radiator fan shroud in accordance with the teachings of
the present invention;
[0016] FIG. 3 is an exploded perspective view showing the radiator
fan shroud of FIG. 2 in isolation;
[0017] FIG. 4 is a cross-sectional view of the ring extension for
the fan shroud shown in FIG. 2; and
[0018] FIG. 5 is a perspective view of a second embodiment of a fan
shroud, made in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] A currently preferred embodiment of the present invention
will now be described with reference to the figures, wherein like
numbers indicate like parts. Referring first to FIG. 1, a schematic
sketch of the engine compartment of a truck 80 is shown, a partial
outline of the truck 80 contour being shown in phantom. Although
the present invention may be applied to other vehicles, such as
passenger cars, vans, sports utility vehicles, and the like, the
preferred embodiment will be described with reference to a
truck--for example, a Class 8 commercial truck. A conventional
engine 82 (also shown in phantom) is mounted inside the engine
compartment of the truck 80. In addition to the engine 82, a number
of auxiliary components are typically disposed in the engine
compartment, denoted generically in FIG. 1 as 84 and 86, such as an
alternator, starter motor, oil cooler, electronic control devices,
pollution control devices, fluid reservoirs, and the like, and may
include elements such as hoses, belts, cables, seals. A radiator 96
is disposed near the front of the truck 80, the radiator 96
receiving fluid coolant from the engine 82, cooling the fluid via
convection of air through the radiator 96, and returning the
coolant to the engine 82.
[0020] A radiator fan shroud 90 is attached to overlie a portion of
the rear face of the radiator 96. An engine-driven fan 88 is
disposed rearwardly of the radiator 96 and includes a plurality of
blades that are substantially enclosed about their radial periphery
by a rearwardly-extending ring portion 92 of the radiator fan
shroud. The fan 88 is oriented such that during operation, the fan
88 draws air rearwardly, through the radiator 96, which airflow may
be further enhanced by the forward motion of the truck 80 (if any),
as indicated by the arrows 98. After passing through the radiator
96 and past the fan 88, the airflow encounters the engine 82,
creating a local region of relatively high pressure as the airflow
must turn to get around the engine 82. It will be appreciated by a
person of skill in the art that this high-pressure region behind
the fan 88 hinders the flow of air, thereby decreasing the airflow
that the fan 88 can produce through the radiator 96. Moreover, in
prior art systems the fan-induced airflow rearwardly of the fan 88
is generally ignored, with no means provided to productively manage
the airflow.
[0021] Refer now to FIG. 2, which shows the same truck 80 having
the same engine 82 and auxiliary components 84, 86. The fan 88 and
radiator 96 may also be the same as the corresponding components
identified in the prior art system shown in FIG. 1. The radiator
fan shroud 100, however, is significantly different from the fan
shroud 90 of the above-described prior art system. In particular,
the fan shroud 100 has a ring assembly 102 that includes a
plurality of openings or ports disposed between and defined by a
plurality of vanes 106. The plurality of ports are selectively
located to produce a number of airflow streams that may be
directed, for example, toward or away from particular auxiliary
components 84, 86--for example, components 84, 86 that would
benefit from additional air convention, as indicated
diagramatically with arrows 98'.
[0022] FIG. 3 is an exploded view of the fan shroud 100, which in
this embodiment comprises two members, a main shroud portion 110
having a peripheral cover portion 112 and a main ring portion 114,
and a ring extension 120 that engages the main ring portion 114.
The ring assembly 102 (see FIG. 2), therefore, includes the main
ring portion 114 and the ring extension 120. Although the cover
portion 112 is shown as a substantially rectilinear member, it is
contemplated that the cover portion 112 may be contoured to improve
airflow through the radiator and/or alternatively shaped, for
example, to provide clearance for other components in the engine
compartment. The main shroud portion 110 may be, for example, a
conventional fan shroud modified to shorten the main ring portion
114. An example of a prior art fan shroud suitable for use as the
main shroud portion 110 is shown in U.S. Design Pat. No. D440,929,
which is hereby incorporated by reference. It is also contemplated
that the main shroud portion 110 may be formed of two or more
pieces that are joined together--for example, with connecting
hardware--in order to facilitate installation and maintenance of
the fan shroud 100.
[0023] As seen most clearly in FIG. 3, the fluted vanes 106 of the
ring extension 120 define a plurality of ports 104 that are
disposed just downstream of the blades of the fan 88. The ports 104
are located in the region of relatively high pressure between the
fan 88 and the engine 82 and, therefore, the ports 104 provide a
relatively low pressure outlet for the air. By judicious placement
of the ports 104, the airflow may be directed in a desired
direction to optimize the airflow in the engine compartment. In
addition, the ports 104 provide a larger area for the airflow
behind the fan 88 (as compared with a conventional ring of the same
length) and therefore will relieve some of the pressure between the
fan 88 and the engine 82, increasing the efficiency of the fan and
allowing a greater airflow through the radiator 96.
[0024] In this embodiment, the ring extension 120 includes a
circular flange 122 that may provide a friction fit with the main
ring portion 114 for slidably attaching the ring extension 120 to
the main shroud portion 110. The ring extension 120 may include one
or more apertures 124 to accommodate attachment hardware (not
shown) for locking the ring extension 120 to the main ring portion
114.
[0025] FIG. 4 shows a cross-sectional side view of the ring
extension 120 with the main shroud portion 110 shown in phantom. As
seen most clearly in this view, the vanes 106 of the ring extension
120 may optionally be fluted or curve outwardly to further manage
the airflow rearward of the blades of the fan 88. Also, it is
contemplated that the vanes 106 may extend varying distances
rearwardly to optimize the airflow for a particular vehicle.
[0026] It will be appreciated that the use of the ring extension
120 allows a designer to optimize the flow in a particular vehicle
configuration by changing a single, relatively inexpensive part,
rather than having to redesign an entire fan shroud.
[0027] Another embodiment of a radiator fan shroud 200, according
to the present invention, is shown in FIG. 5. It will be readily
apparent to the artisan that this fan shroud 200 shares many of the
aspects of the fan shroud 100 discussed above and, for clarity, the
common aspects will not be reiterated here. In the fan shroud 200
the ring assembly 202 is formed integrally with the main shroud
portion 210. It will be appreciated that the integral construction
has obvious advantages in manufacturing costs and reliability. The
ring assembly 202 includes a plurality of ports 204 and vanes 206
to allow the designer to better manage the airflow in the engine
compartment, providing improved airflow through the radiator 96 and
directing airflow to specific areas.
[0028] The main shroud portion 210 may be formed with an upper
portion 211 and a separable lower portion 213. The upper shroud
portion 211 is provided with a flange 215 that overlaps the lower
portion 213 to facilitate alignment and attachment of the upper and
lower portions 211, 213. It will be appreciated that the mechanical
connection between the upper and lower portions 211, 213 may be
accomplished by any convenient mechanism, including friction
fitting or various attachment hardware, as are well known in the
art. It will also be appreciated that providing the fan shroud 200
in two (or more) portions will facilitate installation and/or
removal of the fan shroud 200, particularly in the common situation
wherein clearance is limited.
[0029] The lower portion 213 of the fan shroud 200 shown in FIG. 5
includes an optional lower deflector portion 217 that extends below
the fan 88 and generally deflects airflow rearwardly. It is known
that in certain circumstances, generally when the vehicle is
stationary, a portion of the airflow from the fan 88 (see, FIG. 2)
that is deflected downwardly by the engine 82 can travel under the
front of the vehicle and be recirculated by the fan 88 through the
radiator 96. This air is, of course, warmer than the ambient air
and it is therefore desirable to prevent recirculation through the
radiator 96. The lower deflector portion 217 provides a barrier
that tends to urge the air rearwardly to prevent or reduce such
warm air circulation.
[0030] The fan shroud of the present invention may be made from any
suitable materials as are well known in the art for fan shroud,
including, for example, certain polymeric materials, composite
materials (including fiberglass), or formable metals. The fan
shroud must be rugged enough to endure for long durations the
relatively hot and mechanically agitated environment in the engine
compartment while having sufficient rigidity and dimensional
stability to retain a relatively close tolerance with the fan. It
is also desirable that the fan shroud be as lightweight as
possible.
[0031] While the preferred embodiment of the invention has been
illustrated and described, it will be appreciated that various
changes can be made therein without departing from the spirit and
scope of the invention.
* * * * *